Valve and valve-grid support for air-compressors.



6 m; RICHARD-S, VALVE AND VALVE GRID FOR AIR COMPRESSORS.

a 'AFPVLWATIONHLED DIE-(2.6, 1915. 1,287,751,

' Pate nted B60417, 1918.

3 SHEETS-SHEET I.

G. M; RICHARDS. VALVE AND VALVE GRID SUPPQBT FOR AIR COMP RESSORS.

APPLICATIONIlLE D DEC. 6, i915.

avweuto'v To all whom it may concern sylvania,'hav.e invented a certain new and I VALVE AND VALVE-GRID .Specification of Letters Patent.

SUPPORT- FOR AIacoMrREssoas.

' Patented Dec. 17, 1918.

i Application filed DecemberS, 1915. Serial No. 65,205..

Be it known that I, GEORGE M. RIoHARDs, a citizen of the United States, residing at 4438 N, th street, Philadelphia, in the county of Philadelphia and State of Pennuseful Valve and Valve-Grid Support for Air-Compressors, of which the following'is pressor Q valve unit at the center from a a specification;

The purpose of my invention is to reduce the clearance of discharge-valves for air compressors by reducing the thickness ofthe' valve grid.

A further purpose of my invention is to support the gridof a removable air comspider or other part of the unit, so that the 'grid may be stiffened or," for the same de- I ture of gree of stiffness, may be made of thinner material. i

A further purpose of my invention is to reduce the clearance for air inlet valves and improve .the spring closure for seating them.

Further purposes of my invention will appear in .the specification and the claims hereof.

I have preferred to illustrate my invention by but a few of the many forms in which it may appear, selecting therefor forms which are practical, efiiclent and 1nexpensivefand which at the same time well illustrate the purposes of my invention} Figure 11 is a top plan view of the one form of my invention as applied to removble discharge air compressor valve units.

i Fig; 2 is a central vertical section inthe position shown by line 22 of Fig. 1, but showing additional parts. c i

Fig. 3 is a broken perspective view of the valve grid and two valves used therewith, shown inseparatedpositions.

Fig. 4 is .a section corresponding inposi- "tion to Fig. 2 taken of a removable inlet surface 12 of the'rim of the spider, while valve unitand associated parts.

showing Figs!) and 7 are enlarged sectional views of portions'fof Fig. 4:.

' of he valves shownin Figs. 1 and 5.

Figs. ,9 and 10 are central vertical sectional views of modified forms of removable air inlet compressor valve units.

Fig. 5 is a top plan view broken in part," the spider, grid andvalve-struc Fig. 8 is a broken 'perspective view (sf-am.

. In thedrawings, similar numerals refer to corresponding parts.

i In air compressor work the clearance between the valves and the interior ofthe cylinder is waste space. This is true both of the inlet and discharge valves. They-receive and retain air under pressure which should be expelled by the discharge stroke and which expands to fill part'of the'space in the cylinder inthe place of additional in let air which would otherwise flow in.- The result islthat the efliciency is lowered. My

invention is designed to reduce the thickness of-the grids used, to give themiadded stifinessagainst the pressures applied and t0 a increase the efiiciency of adequately: fiat .in--

let valve springs. 4

\ Applying my inventionto the discharge valve shown inFigsrl to 3, I have shown the cylinder 11 apertured at 12- to receivev a valve unit grid 13 and spider 14: held together and in place by a set screw 15, pressing upon the boss 16 of the spider. The

' screw is held in any suitable support 17..

The gridis faced at 18 in the usual manner to seal tlghtly against the annular facing of the cylinder.

vThe valve grid carries seats 19, 20, 21, 22

surrounding ports 23 and 24 which are interrupted at intervals by radial. webs 25,

26. The valves 27, 28 are-flanged for stiffening purposes, preferably having most of the fianging above as at 29, 30, 31, 32

inorder to reduce the volume of clearance all space upon the sides toward theseats,

in recesses 38, in any suitable number of spider arms 39,40, 11. I

The guide for the valve 27 is'the inner the valve 28 is guided ripen the inside :by the-outer edges 43 of wings 4A upon a stud 45, seated in -a recess 46' in the boss of the spider and secured to the valvegrid at 47.

The stud is shown as secured in the spider and alsoin thejgridand is'preferably inserted in the grid first and screwed home until the lower parts of the wings 44cengage with the annuar face 48 about the' aperture in: the center of the grid. In assemblage 4 valve.

of the parts, the valves and springs may then be put in place with the parts inverted and the grid with the stud in it can be screwed into the boss of the spider until the proper contact of the rim of the spider with the grid has been secured.

It will be seen that the pressures upon the grid of the valve will be "in a downward direction in Fig. 2 and that the support of the middle of the grid from the spider against strains in this direction, applying the principles applicable to the design-of spans under load, makes it possible to reduce the thickness of the grid to less than half of that of the grid required if there be no support at the middle. Moreover, the

tightening of the spider upon the stud until theriin of the spider presses the grid places the stud under tension and takes up any lost motion between the threads of the grid and spider on the one hand and the stud on the other, so that there is no lost motion before the grid receives the intended central support. This advantage will be pointed out in more detail in connection with Fig. 4 and the construction by which this lost motion between thethreads is initially taken up as shown in the enlargedviews in Figs.

are of the same general form as in Fig. 1

but are correspondingly faced in an opposite direction. They are not flanged upon their under sides, as they-make their sealing contact above by flanges 38. 3%; 35, 36", engaging with tlanges 19, 20'. 21. 22 upon the under or fbase" side ofthe grid.

The valves are held in place by coils &9 of a spring or springs 50 here shown as a single length of wire passed through the lingers 51 of a skeleton spring support-52,. so that. each coil or spring shall press upon both of the valves. The wire is shown as terminating with its ends together at The inner valve has a smaller area exposed to the fluid pressure than the. outer But, as the inner valve i's-furt-her radially from the points of supportfof the springs than the outer valve, it will be evident that the leverage component ofits turn ing moment upon the coils will be greaterthan that of the outer valve and that the inner valve may be made to lift uniformly with the outer valve or, preferably. even more readilythaii'the outer valve. If this relative excess of leverage over difference inscrew were used.

area subject to pressure exist in favor of the inner valve, it will open first and to a greater extent than the'outer valve. This is a desirable, though not a necessary condition.

Both the inner and outer. valves in this form are shown as guided by the ribs 54 of the valve support 52,which ribs rest between them and space the valves at the same time that they guide both ofthem.

The opening of the valves need not be great and may be limited by the stiffness of the spring app lied or by ultimate engagement with the adjoining surface of the support.

Ihe pressure upon the grid is upward in Fig. 4, whereas the strain between the threads of the stud and those of the spider and grid would normally be downward in the spider and upward in the grid, leaving the lost motion between the threads to be taken up by movement of the grid before it received the'support of the stud if a plain strains between the threads of the stud and those of the grid and spider I use the fol-.

construction utilized to retain the valve sup: port 52 in position.

The stud is headed at 5, engaging the outer surface of the support and is screwed in place so as to bring pressure upon the head against the support and, by re-action, to take up the lost motion between the threads'of the stud and the iiiterior threads of the grid.

In the construction shown, and to avoid undue strain upon the support, I have used a spacer 56 to fill in the distance between the interior of the boss 57, upon the valve sup'portand the face of the grid,.in preference to filling this space by a collar integral with the support.

The means utilized in Fig. l for taking up the lost motion between the threads of the stud and the threads in the boss 16 of the spider, is by means of a nut 58 upon the stud, bearing against the undersurface 58 of the boss. preferably recessed at this point .to give additional room for the nut.

The condition'of the threads produced by ,these several means is best seen in Figs. 6 and 7 where the faces 59 of the thread upon the stud are firmly held against the faces 60 of the thread in the grid and the same faces also in the boss of the spider. T endency of the grid to move upwardly with respect to the studfis blocked by the maintainediengagement of these faces of the stud and grid.- while tendency of the stud to move bodily in toward the boss of the spider is prevented bv the engagement of the faces 61 of the threads of the stud with the faces 62 ofthethreads of the nut. and the tight In order to reverse the pressure of the 'n'i'it' against the under surface of the Tense-c.

cylinder shown, valves,-andassociated partsand set screw to'hold'thevalve units in position, are intendedto beidentical with those in Fig. 4,'-but there are differences in the spiderand;stufdin' both constructions and in thcgrid in Fig. 10. I 1 0 by aalock nut-63 uponwhich the set screw taken up by.a .collar 64, so that the parts are-held solidly together between the head 55 and the endof the screw.

-The form-shownin Fig. is identical with that. in Fig. 9 in the functioning of the 'parts when secured, but the spider, grid and collar 64 are'here formed in a single structure and the stud 39 is not threaded into the other parts 'at al l, but into-the nut 63 2'5-al0ne.

The pressure upon. the valve grid. in the forms shown in Figs. to lOwill'be in the direction-of "the boss 16, placing the intermediate parts under compression. The intermediate parts .fully support the grid at the center." v Y It will'be evident that in all of the forms of my invention the valve grid is supported near to its center against strains in the direction in which the air pressure hears,

shortening the span subject-to air pressure to approximately half of its diameter and I permitting the use of much thinner material than could otherwise be'used.

-While the compact flat form of sprin shown in Figs. 4, 5, 9 and 10 is particularly desirable with inlet valves on account of its high eiiiciency and the short space axial of the grid which is taken upby it (the shortening of thisclearance space being very desirable) it will be evident that this form of torsion coil flat spring may also. be used with discharge valves and offers advantages in simplicity, efiiciency, long life and reliability, wherever used.

Having thus described my invention, what I claim as new and desire to secure by Let ters Patent is A 1. In a device of the character stated, a

valve grid, a valve therefor, a spider for the grid, engaging the grid at its circumference, and a threaded connection between the grid and spider having the lost motion between a the threads taken up in the direction of the closing movement of the-Valve.

2. In a device of the character stated, an inlet air valve unit comprising a' grid, valves on one side of the grid, springs engaging -;Th e f. stud 39 is passed directly through the boss "16 o'f'the spider, preferably-being threaded into=itsand being-theldin position '15 bears. j-Th'e. entire space between the 5 spider and the lower faceof the boss'16 is havin the valves, a support for the springs, a. sp der on the opposite side of the grid, en-' gagingthe grid at its circumference, and aconnection between the grid and the spider, Inthe formsshowniin Figs. 9, and, l0, the

normally under compression and. located centrallywith respectto the grid. a I ,3. In a device of the. charactenstated, an'- inlet air valve unit comprising a grid, valves on one sideof; the grid, springs engaging the valves,-a support-for the springs, aspider' on the opposite side of the grid, engaging;

the gridatits' circumference, and a connection between the grid and thespider having its'play-in compressive'direction taken up." 14. In a device of the,character stated, a valve grid, alspideron one side ofthe grid, engaging the grid atits circumference, valves on' the opposite, side of the grid,

springs for the valves, a support for the springs and a connection for holding the support to the grid and the grid to the spider, normally ainder tension in the parts lying in the' grid and in the spider.

=5. Ina device of the character stated, a

-,circular grid, valve structure on one side of the grid, at spider on the opposite side of the grid, the grid and spider being rigidly held away from each other close to the center and retaining means passing through the grid .:at the center and holding the valveconstruction in position.

6. In a device of thecharacter stated, an

' integral grid and spider having rigid connection between them about the center, in combinationwith a valve structure on the 1 opposite siderof the grid from the spider 1 andmeans' for securing the valve structure 3 in position. I

7. In a device of, the character stated, a grid having annular valve openings, sepa rate annular valves engaging the'openings, gsprings for the annular valves, a support for the springs, aguide for the valves carried .by the support, a-spider on-the opposite side of the gridand a bolt passing through the support into the spider.

' "8. In a device of the character stated, a valvegrid, annular valves. of different diameter for the, grid, a valve spring support and a spring for the valves engaging with the 1 support at two 'points. and at an intermediate point engaging with the valves;

"' .9. In adevice of the character stated, a

valve grid, annular valves of different diameter forthe grid, a valve spring support arms and aspring for the valves engaging with the arms of the support and coiled at an intermediate point to engage with the valves f 10. In a device of the character stated, a valve grid, annular valves of different diameter for the grid, a valve spring support having arms and a spring for the valves engaging with the arms of the support and coiled at an intermediate point to engage with the valves at different distances radially from the points of engagement of the ings for the valves.

11. In a device of the character stated, a-

valve grid, a plurality of annular valves of difierent diameter therefor, a valve spring support connected with the middle of the valve grid and having radially extending arms and. a wire spring engaging adjoining arms, coiled between the arms, extending inwardly toward the center of the support from the point of engagement and making contact with the valves.

12. In a device of the character stated, a

valve grid, a'plurality of annular valves of diflerent diameter therefor, a valve spring support having radially extending armsv and a wire spring engaging adjoining arms, coiled between the arms, extending lnwardly toward the center of the support from the point of engagement and making contact with the valves and adapted to compensate for smaller area of interiorly located valves by providingthem with a larger leverage. GEORGE M. RICHARDS.

Witnesses:

7 WM. STEELL JAoKsoN,

J. LUTHERIA KAUFFMAN. 

